Monitoring and control of industrial processes has undergone a series of developments in the last forty years. These developments can be characterized chronologically by the use of distributed instrumentation associated with the process throughout the plant; to the use of electrical instrumentation for monitoring plant conditions; to the use of centralizing the electrical instrumentation in large control rooms; and in more recent times through the use of centralized computer based operator displays using CRT monitors to present information regarding the process variables, trends of past history of selected variables and alarm annunciation. Present day centralized operator consoles may be grouped in units of two or more to provide multiple displays; with for instance one console showing the overall process, a second console allowing the operator to monitor a group of specific data points, and sometimes a third console dedicated to alarm annunciation. Associated with such operator monitors has typically been dedicated keyboards for the input of information by the operator; specifically with respect to set point values, alarm limits, and other input parameters.
Thus, over the years there has been a steady evolution in process instrumentation and control to the point where it has been found desirable to concentrate operator monitoring and oversee control at a single location in order to provide complete plant overview, including alarm review and plant operation in general.
A typical prior art system with these capabilities is the TDC-2000 system of Honeywell, Inc. In this system, multiple monitors and associated keyboards are utilized to oversee plant operations which in combination with various process interfaces provides for the overall monitoring and alarm annunciation of the entire process. A Honeywell, Inc. publication entitled "An Evolutionary Look at Centralized Operation/2", copyright 1977, by Henry Marks, describes this prior art system and shows that multiple CRT monitors are used in conjunction with associated keyboards, pen recorders and printers.
A fundamental difference between this prior art system and the present man-machine interface is that the former utilizes dedicated keyboards for the selection of the portion of the plant to be displayed as well as for responding to alarm conditions and for setting various parameters. The present invention when utilized for operator monitoring and control need not use a keyboard, but instead performs its functions through graphic displays with the response by the operator made through a touch screen associated with the monitor. In this way, the man-machine interface can be made more user friendly. It is also more flexible with respect to the type of response required by the operator and the way that the response is input by the operator. Indeed, the present invention provides for generation of screen generated "buttons" which can change color upon activation by the operator and which can take on various colors and blinking states to draw attention to the response required. This overall graphic display approach is believed to be much more operator friendly and is readily adaptable to changing circumstances of the process under control.
Furthermore, the present invention provides a man-machine interface with a built-in high level graphic language having commands which provide easy design and configuration of the overall process to be controlled. The high level graphic language includes built-in templates defining particular graphic designs which further helps the designer and configurer to generate a desired overall configuration of the process to be initialized or modified and in the way it is to be monitored and controlled.
In addition, up to sixteen different colors from 512 permissible colors may be simultaneously displayed in each of a plurality of zones; each zone occupying a region of the CRT screen. In this way, simulation of pen recorders with multiple colors can be obtained with a high resolution, including accurate color line depiction with the new neighborhood of line crossings, something hitherto believed to be unobtainable.
The present invention also incorporates other video features including the ability to shift sub-pictures on the screen and to manipulate the screen information in a high speed dynamic fashion which further enhances the graphic capability and therefore man-machine friendliness of the present invention.
Thus although dynamic graphics and process control exist in the prior art, the present invention provides the means for implementing such graphics in a straightforward fashion as well as providing greater graphic capabilities.
The Anaconda Advanced Technology (ANATEC) of Los Angeles, CA. provides a process control system with CRT monitors, which like the Honeywell TDC-2000, utilizes keyboards in association with monitors for operator overseeing and control and further utilizes a computer control and display system called CRISP.RTM. for implementing the desired process. The graphics associated with this system utilize 256 standard engineering symbols and characters to implement the displays and to design overview and process loop control. Each symbol and character occupies a given screen area (typically on the order of fifty pixels) and in each such area only two colors (background and foreground) can be displayed. Although such screen areas are relatively small, graphic representations of intersecting lines cannot show such lines as two distinct colors if the background is to have a unique color. The high level graphic language of the present invention is procedurally oriented without dedicated symbol types and thereby the colors associated with any subset of the screen is not limited to two colors as determined by the symbol type but can be any one of up to sixteen different colors for the corresponding zone in which that portion of the screen resides. This color determination can be made on the pixel level for each pixel in the zone. Differently colored intersecting or adjacent lines are thus possible in combination with a unique background color. The end result is that the graphic displays of the present invention provide high color resolution on a pixel by pixel basis which is easy to implement and modify.
Another CRT based operator work station for process control is that of the Foxboro Co., of Foxboro, MA., known as VIDEO SPEC.TM. subsystem. The VIDEO SPEC subsystem is a subset of the SPEC 200.TM. management control system sold by Foxboro. The subsystem is the vehicle by which display and response to the overall process is made by the operator. Process overviews, trends, records of variables and alarm summaries are available with this system. It, like the previously mentioned prior art process control systems, utilizes a keyboard in association with a monitor(s) for selection of the process portions to be overseen as well as to provide input to the overall process. The use of a graphic display which is touch sensitive for operator input is neither described nor suggested by these prior art systems. Thus although the CRT in the Foxboro system may be used to label associated keys on the keyboard through alignment with the keys, the actual implementation of buttons and other devices on the display for user input and control is not shown or suggested by this product.
Similarly, a distributed process control system called the DCI-4000 by Fischer & Porter Co. of Warminster, PA. utilizes a black and white TV scan CRT terminal with an associated special keyboard that is used as the operator panel.